Typed Arrays is a relatively new feature in javascript. They are designed to provide an easy way to work with binary data and structures, that was hardly possible before.

Initially, Typed Arrays were introduced for WebGL APIs. The reason behind this is that converting and guessing the type of standard JavaScript array might be too slow, while C API which is backing up WebGL might access already allocated in memory typed array.

Typed Arrays are part of ECMAScript 2015 (also known as ES6) specification.

Browser support

The main "problem" with browser support is IE9, which is still quite popular, as well as some browsers handling typed arrays slightly different:

IE10 (and IE 10&11 mobile) does not support Uint8ClampedArray
Safari 5.1 does not support Float64Array
Firefox 14 and under do not have DataView yet.
In versions before Safari 6, Typed Arrays are much slower than Array Objects.
ArrayBuffer has no slice method in IE 10.
Creating typed array

Typed array creation is relatively easy:

var arr = new Uint16Array(10);
arr[0] = 0xFFFF;
console.log(arr[0]);

Argument we are passing to array constructor is the number of elements in array (in the example above we are creating array of 10 uint16 numbers, which will take 20 bytes of memory).

Typed arrays could be following

Int8Array

size in bytes: 1

description: 8-bit two's complement signed integer

Web IDL type: byte

C type: int8_t

JavaScript Operators & Typed Arrays

You might expect that all the operations on typed arrays will be done on bits this array contains. Apparently, that's not true.

Sequential reads/writes to both types of arrays are nearly equally fast, while Array Object will be slower for out-of-the-bounds writes (as it will require reallocation).

Conclusions here:

Typed Arrays are beneficial when you need long-sustained array with specific size and type, and for use cases mentioned above
Array Objects are beneficial when you need dynamic array or when you need temporary array (because of allocation method)